Lubricant composition



United States atent O LUBRICANT COMPOSITION Ernest R. Vierk, Lansing,111., and Theodore J. Karr,

East Chicago, Ind., assignors to Sinclair Refining Company, New York,N.Y., a corporation of Maine No Drawing. Filed Oct. 18, 1955, Ser. No.541,295

3 Claims. (Cl. 252-55) This invention relates to a new protectivelubricant composition and more particularly relates to a lubricantcomposition especially useful for application in conjunction with wireropes, flexible metallic strands and similar metallic articles.

Lubricants suitable for use as a protective lubricant must have a seriesof properties which are essentially inconsistent. For example, thelubricant should have a high softening point to avoid dripping over agreat range of temperature and still possess good flexibility at lowtemperatures so that brittleness resulting in cracking, peeling andchipping does not occur. The problems presented by these essentiallyinconsistent properties has resulted in the development of numerouslubricants characterized as useful under a particular series ofconditions but possibly not of general use. Additives have been employedin attempts to adjust certain properties of these lubricants. This, ofcourse, is expensive and wasteful of the additives because they shouldbe used to obtain properties which cannot be otherwise economicallyobtained.

In the course of our investigations of lubricants, especially thoseadapted for use as protective lubricants,

we have discovered a new composition of matter which is characterized byoutstanding properties in each of the extremes to which the lubricantsnormally are subjected. In accordance with our invention a lubricant canbe produced which is characterized by case of application, the action ofa plastic solid after solidification and which has a high flow or driptemperature and good flexibility at low temperatures.

The novel compositions constituting our invention in protectivelubricants employ a specially blown asphalt, polyethylene and aviscosity reducing mineral oil as the essential constituents. While manydifferent combinations of the various materials are effective inproducing lubricants we have found that considering functionalproperties in relation to the cost of the material produced,compositions containing about 2 to weight percent polyethylene, about 55to 75 weight percent blown asphalt and substantially the balance amineral lubricating oil, have highly satisfactory properties. Preferredcompositions contain about 3 to 6 percent polyethylene, about 60 to 70percent blown asphalt and substantially the balance oil.

The effect of varying the compositions, for example, by changing thequantity of polyethylene can best be seen in the data in the followingtable. To conduct these tests a solvent refined Mid-Continent neutraloil having a viscosity of about 155 S'US at 100 F. was employed. Blownasphalt having a penetration of 7 at 77 F. (100 gram needle) obtained byair blowing an asphalt having a viscosity of 1000 furol seconds at 210F. to a softening point (R and B) of 210 F. and a polyethylene having amolecular weight of about 2000 were employed. The data are:

2,947,697 Patented Aug. 2, 1960 TABLE 1 Composition, Parts:

Oil

Asphalt. Polyethylene." Laboratory Tests: Flow (Drip) Temperature, F.Softening Point gfi ing & Ball),

Flexibility at '-5 F1, Wire Rope Coated with Lubricant.

Brittle Point,

F. Metal Strip Coated with Lubricant.

Few tiny cracks Few tiny cracks Few tiny 0 cracks cracks.

These data evidence the surprising properties of our compositions; thatis, improved high temperature characteristics are obtained withoutsimultaneously experiencing a detrimental effect on the low temperaturecharacteristics of the resulting compositions, an undesirable effectwhich frequently occurs upon making additions to a base composition. Itis also apparent that high resistance to flow and a sufliciently highsoftening point are obtained with compositions containing 2 or morepercent polyethylene. To obtain optimum flexibility of the lubricant asevidenced by applying the lubricant to a wire rope strand, cooling to 5F. and flexing, larger quantities of the polyethylene, for example about5 percent, are needed to result in a product without any cracks. It willthus be apparent that within the ranges above established there will bean optimum concentration of the various components depending upon thefunctional property most desired.

Compositions of the present invention may be prepared by blending thepolyethylene and blown asphalt in the oil component separately in anyorder or viscous blends of blown asphalt and polyethylene may bepreformed and the oil added as needed to obtain the final composi= tion.An advantageous method involves simply heating the blown asphalt andpolyethylene at an elevated temperature above the melting point of bothcomponents for example above about 275 or 300 F. The melted componentsare then stirred to insure homogeneity. Such oil as is needed forspecification viscosity can then be incorporated, with stirring, and themixture then permitted to cool to room temperature, preferably withoutthe use of cooling means. If desired, compositions can be prepared andstored for subsequent use or the com= positions can be prepared at thetime that application to the material to be protected is desired. Byemploying the latter procedure a heat economy is obtained since themelted composition can be applied directly to the object withoutintervening solidification and its attendant remelting to obtain thenecessary fluidity. This is possible since application of lubricants ofthis nature normally is brought about by melting a lubricant andpainting or otherwise applying it to the surface. Where a wire ropecomprised of a plurality of strands is to be coated with the lubricant,suflicient fluidity to penetrate to all surfaces is, of course,required. When the lubricant is applied to each strand separately asduring the, manufacture of a wire rope, surfaces, crevices and the likebeing extremely small, fluidity of a lubricant again is highlyimportant. Other methods of application can be used at the option of anoperator.

The invention will be described further in conjunction with thefollowing specific example. It is to be under- Example About 61 poundsof blown asphalt having a softening point of 210 F. (R. and B.) .and apenetration of 7 at 77 F. with a 100 gram needle were melted by heatingto a temperature of about 275 to 300 F. About pounds of polyethylenehaving a molecularweight of about 2000, a specific gravity of 0.92, amelting point of about 100 C. and a viscosity of 185 furol seconds at140 C. were added to the melted asphalt and the mixture was stirreduntil the polyethylene was melted and blended throughout the asphalt;stirring for about one-half hour was needed. About 34 pounds of a Mid-Continent solvent refined neutral oil having a viscosity of about 155SUS at 100 F. were added while stirring the mixture of blown asphalt andpolyethylene. Stirring was continued until the mixture was homogeneousand the composition was then permitted to cool to room temperature.Samples of the resulting composition were tested to determine variousproperties; the results are as follows:

TABLE II Laboratory Tests: 1

Specific Gravity (SO/60 F 0.9582. Flash, F 440. Furol Viscosity at 250 FFurol Viscosity at 275 F Penetration at 77 F., 100 g. Ne Softening Point(R & B), F

Flow (Drip) Temperature, F 170. Flexibility at -5 F., Wire Rope Coatedwith Lubri- No cracks.

cant. Brittle Point, F. Metal Strip Coated with Lubricant. 40. SaltSpray Rust Test, Days Pass.

4-Ball EP Test, Kg. Load to Incipient Weld The functional data of theabove table were obtained by various commercial tests. For example,dripping point is determined by dip coating a test panel with lubricantpreheated to250 F. The panel is then put into an oven at 80 F. and theoven temperature elevated 10 every 24 hours until dripping occurs, thetemperature of dripping being reported. To determine low temperatureflexibility a wire rope strand is coated with lubricant preheated to 250F., the coated strand is then cooled to 5 F. and flexed. Visualobservation is then made and the presence or absence of'any cracking orbreak in the lubricant film is noted and recorded. Brittle point isdetermined by coating a metal strip with lubricant preheated to 250 -F.The coating strip is then placed in a cold cabinet in which thetemperature is progressively lowered. At 10 intervals the strip isflexed and ob- :served for cracking and other evidence of brittleness inthe lubricant film with the temperature of faulting being noted andrecorded.

The polyethylene used in the example is preferred and has a molecularweight of about 2000. Other polyethylenes which can be employed in thepresent invention :are normally solid at room temperature and range inmolecular Weight from about 1000 to 23,000 or more, and preferably about1000 to 5000 to take advantage of ease of handling. The polyethylenesmay, if desired, be those which contain so-called terminal hydroxylgroups, that is a hydroxyl radical attached to one of the last fewcarbon atoms, for example, one of the last five carbon atoms.Polyethylenes including those containing terminal hydroxyl groups arecommercially available and the commercial products are employed in thepresent invention.

, The blown asphalt component of the present invention is present inamounts varying from about 55 to 75 weight percent. .The blown asphaltis prepared by a procedure consisting of air blowing a suitable chargestock, for example, one having a viscosity of about 900 to 1100 furol sesn sat 210 u t h Swelling P in of the blown asphalt is within the rangeof about 200 to 225 F. The resulting blown asphalt will normallyevidence a penetration of less than about 15 for example, from about 3to 15 (100 gram needle at 77 F.). Air blowing to produce blown asphaltsis conducted according to known procedures at elevated temperatures, forexample, 500 F. with or without the use of conventional catalysts.

The mineral oil component of the compositions of the present inventionis present in an amount suificient to render the composition of aviscosity determined pri: marily by specifications. Normally this amountwill range from about 20 to 45 or more percent by weight. The oil can bea Mid-Continent, naphthenic, or paraffinic base lubricating oilfraction, for example a neutral oil, and can be conventionally refinedor preferably solvent refined by conventional refinery procedures. Theamount and viscosity of the oil employed is adapted to characterize theproduct composition with a viscosity of about 150 to 300 furol secondsat 250 -F. It is preferred to employ neutral oils having viscositieswithin the range of about to 450 SUS at F. v

While the compositions of the present invention have been described ascontaining as the essential constituent blown asphalt, polyethylene anda viscosity reducing mineral oil it should be understood that othercomponents such as antioxidant and extreme pressure additives and thelike may be included so long as they do not deleteriously affect thefunctional properties of the composition. On the other hand, anoutstanding advantage of the present invention is that its functionalproperties are such that additives such as lead naphthanate, an extremepressure agent, may not be necessary to meet the usual specification.Also in the data in Example I it can be seen that our compositionsuccessfully passed the salt spray rust test without the necessity ofemploying an anti-rust additive.

In the foregoing we have described compositions which are especiallyuseful as protective lubricants for wire ropes, flexible metallicstrands and similar metallic articles. These compositions areparticularly advantageous in that they possess superior properties atthe extrem of conditions encountered in use.

We claim:

1. A protective lubricant consisting essentially of about 2 to 10percent by weight of a normally solid polyethylene having a molecularweight of about 1000 to 23,000, about 55 to 75 percent by weight ofblown asphalt, said blown asphalt having a softening point of about 200to 225 F. and having a penetration at 77 F. (100 gram needle) of lessthan about 15, and a mineral lubricating oil fraction suflicient tocharacterize the lubricant with a viscosity of about to 300 furolseconds at 250 F.

2. The protective lubricant of claim 1 in which the polyethylene contentis about 3 to 6 percent by weight.

3. The protective lubricant of claim 1 in which the polyethylene contentis about 5 percent and has a molecular weight of about 2000.

References Cited in the file of this patent Manufacture and Applicationof Lubricating Greases, by Boner. Copyright October 20, 1954. ReinholdPublishing Corporation, New York. Pages 795-798 perti- Bent.

r in

1. A PROTECTIVE LUBRICANT CONSISTING ESSENTIALLY OF ABOUT 2 TO 10PERCENT BY WEIGHT OF A NORMALLY SOLID POLYETHYLENE HAVING A MOLECULARWEIGHT OF ABOUT 1000 TO 23,000, ABOUT 55 TO 75 PERCENT BY WEIGHT OFBLOWN ASPHALT, SAID BLOWN ASPHALT HAVING A SOFTENING POINT OF ABOUT 200TO 225*F. AND HAVING A PENETRATION AT 77*F (100 GRAM NEELDE) OF LESSTHAN ABOUT 15, AND MINERAL LUBRICATING OIL FRACTION SUFFICIENT TOCHARACTERIZE THE LUBRICANT WITH A VISCOSITY OF ABOUT 150 TO 300 FUROLSECONDS AT 250*F.